The Effect of Spots on the Luminosity Spread of the Pleiades
The Effect of Spots on the Luminosity Spread of the Pleiades
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斑点对昴宿星光度分布的影响
DOI：
10.3847/1538-4357/aaeb9b
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发表时间：
2018-10
影响因子：
4.9
通讯作者：
Herczeg Gregory J.
中科院分区：
文献类型：
--
作者：
Guo Zhen;Gully-Santiago Michael;Herczeg Gregory J.
磁活跃恒星表面的冷点调节它们观测到的亮度和温度，从而影响H-R图上的恒星轨迹。最近的高精度空基光度测量揭示了年轻星团中恒星上斑点的旋转调制，包括对1.25亿年前的昂宿星团的K2监测。然而，光变曲线只揭示了可见光点分布的不对称性，而不是恒星表面斑点的总尺寸，这导致测光和光谱观测测量的斑点覆盖率之间的差异。在本文中，我们模拟光度的变化介绍了随机分布的星点上的125万年的年龄coeval集群。我们的模拟结果表明，随机分布的小斑点的恒星表面可以解释的差异，光度观测只揭示了10%-40%的光谱测量的斑点覆盖率。光球的颜色和亮度的光球温度，光斑覆盖范围和光斑温度的范围内建模。然后将模拟种群的颜色和光度与昴星团成员的光度分布进行比较，排除25%的候选者，这些候选者被盖亚DR 2天体测量确定为非成员。观测到的昴星团成员的光度有0.05 dex的标准偏差，这可以完全解释为恒星到星星的标准偏差为10%的斑点覆盖范围，但平均覆盖面积没有很好的限制。
Cool spots on the surface of magnetically active stars modulate their observed brightnesses and temperatures, thereby affecting the stellar locus on the H-R diagram. Recent high-precision space-based photometric surveys reveal the rotational modulation from spots on stars in young clusters, including K2 monitoring of the 125 Myr old Pleiades cluster. However, light curves reveal only the asymmetries in the visible spot distributions rather than the total sizes of spots on stellar surfaces, which causes a discrepancy between the spot coverage measured by photometric and spectroscopic observations. In this paper, we simulate photometric variability introduced by randomly distributed starspots on a 125 Myr old coeval cluster. Our simulation results show that randomly distributed small spots on the stellar surface would explain the discrepancy that the photometric observations only reveal 10%–40% of the spot coverage measured by spectra. The colors and luminosities of photospheres are modeled for a range of photospheric temperature, spot coverage, and spot temperature. The colors and luminosities of a simulated population are then compared to the luminosity spread of Pleiades members, excluding the 25% of candidates that are identified as non-members with Gaia DR2 astrometry. The observed luminosities of Pleiades members have a standard deviation of 0.05 dex, which could be entirely explained by spots with a star-to-star standard deviation of spot coverage of 10%, but with an average coverage area that is not well constrained.
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附近年轻星团中低质量恒星的经验等时线
影响因子：
4.9
作者：
Herczeg Gregory J.;Hillenbr;Lynne A.;Herczeg GJ
通讯作者：
Herczeg GJ
DOI：
10.1051/0004-6361/201628382
发表时间：
2016-06
期刊：
arXiv: Solar and Stellar Astrophysics
影响因子：
--
作者：
Antonino Francesco Lanza;E. Flaccomio;S. Messina;G. Micela;I. Pagano;G. Leto
通讯作者：
Antonino Francesco Lanza;E. Flaccomio;S. Messina;G. Micela;I. Pagano;G. Leto
DOI：
10.3847/1538-4357/aaa08c
发表时间：
2017-11
期刊：
The Astrophysical Journal
影响因子：
--
作者：
B. Rackham;D. Apai;M. Giampapa
通讯作者：
B. Rackham;D. Apai;M. Giampapa
DOI：
10.1088/0004-637x/738/2/140
发表时间：
2011-01
期刊：
The Astrophysical Journal
影响因子：
--
作者：
T. Hosokawa;S. Offner;M. Krumholz
通讯作者：
T. Hosokawa;S. Offner;M. Krumholz
DOI：
10.1088/0004-6256/148/2/30
发表时间：
2014-06
期刊：
The Astronomical Journal
影响因子：
--
作者：
B. Kamai;F. Vrba;J. Stauffer;K. Stassun
通讯作者：
B. Kamai;F. Vrba;J. Stauffer;K. Stassun